Mi ex vive aquí.

Ex is a very common noun in Spanish, just like in English. It means ex-partner, and it does not show gender by itself.

So mi ex can mean:

• my ex-boyfriend
• my ex-girlfriend
• my ex-partner

If you want to be more specific, Spanish can also say:

• mi exnovio = my ex-boyfriend
• mi exnovia = my ex-girlfriend

Ex itself does not change form for masculine or feminine. It stays ex for everyone.

So you can say:

• Mi ex vive aquí.
• Mi ex trabaja cerca.

If needed, other words in the sentence or the context will show whether the person is male or female.

Because mi here is a possessive adjective, meaning my.

• mi = my
• mí = me, after a preposition

Compare:

• Mi ex vive aquí. = My ex lives here.
• Para mí, es difícil. = For me, it is difficult.

So in this sentence, the correct form is mi without an accent mark.

Spanish often leaves out subject pronouns because the verb ending already gives information about the subject.

Vive is the third person singular form of vivir, so it can mean:

• he lives
• she lives
• it lives
• you live (formal: usted)

Since mi ex is already the subject, adding él or ella would usually be unnecessary:

• Mi ex vive aquí. = normal
• Mi ex, él vive aquí. = unusual unless you want extra emphasis

Vive is the present tense, third person singular form of the verb vivir (to live).

Full present tense of vivir:

• yo vivo
• tú vives
• él/ella/usted vive
• nosotros/nosotras vivimos
• vosotros/vosotras vivís
• ellos/ellas/ustedes viven

So mi ex vive means my ex lives.

It mainly means to live in the sense of residing or having a life.

In Mi ex vive aquí, it clearly means resides here.

Spanish can also use vivir in broader senses, such as:

• Vive feliz. = He/She lives happily.

But in a sentence with aquí, the meaning is very naturally lives here.

That is the most natural word order here:

• Mi ex vive aquí.

Spanish often puts adverbs of place like aquí after the verb.

You could move it for emphasis in some contexts:

• Aquí vive mi ex. = My ex lives here. / It’s here that my ex lives.

But the original version is the neutral, standard order.

In Spain, aquí is much more common in this kind of sentence.

• aquí = here
• acá = here, but more common in many parts of Latin America

In Spain, Mi ex vive aquí sounds the most natural.

The written accent helps show the correct stress: a-QUÍ.

It is a standard spelling rule. You simply need to learn it as aquí, not aqui.

Other common words with a written accent include:

• allí
• también
• sí

A simple pronunciation guide is:

mee eks BEE-beh ah-KEE

More closely:

• mi = mee
• ex = like English ex
• vive = BEE-beh in most of Spain, because v and b are pronounced very similarly in Spanish
• aquí = ah-KEE

In much of Spain, the full sentence flows smoothly: Mi ex vive aquí.

No, not usually. In Spanish, b and v are pronounced very similarly, and neither is usually the strong English v sound.

So vive does not sound like English vee-vay.

It sounds more like:

• BEE-beh

This is normal Spanish pronunciation.

Yes, depending on context, mi ex can refer more generally to a former romantic partner, including an ex-spouse.

If someone wants to be specific, they might say:

• mi exmarido = my ex-husband
• mi exmujer = my ex-wife
• mi exnovio = my ex-boyfriend
• mi exnovia = my ex-girlfriend

But mi ex is very common as a general term.

Yes, but it means something different.

• Mi ex vive aquí. = My ex lives here.
• Mi ex está aquí. = My ex is here.

So:

• vive aquí talks about where the person lives
• está aquí talks about where the person is at the moment

Yes. The Spanish present tense can often correspond to either the simple present or the present continuous in English, depending on context.

So Mi ex vive aquí most naturally means:

• My ex lives here

But in some contexts, it could also be understood as:

• My ex is living here

Still, the default interpretation is usually the simple statement of residence: My ex lives here.

Yes, completely natural.

Mi ex vive aquí is short, normal, and idiomatic Spanish. A speaker in Spain would easily understand it and would not find anything strange about the wording.